Hi, I have setup Redhat Linux 9.0 server with 3 ethernet cards. 1) eth0 for Internet access. 2) eth1 (10.0.0.2) without any connection. 3) eth2 (192.168.0.1) where LAN users are connected. I have setup Apache and sendmail servers on same machine. 202.63.167.192 is a static ip address of domain networkshastrihall.com which is registered. I have stopped iptables and has got only these lines in file "/etc/rc.d/rc.local" ##### touch /var/lock/subsys/local echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE iptables -A FORWARD -i eth2 -j ACCEPT ptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p tcp -m tcp --dport 995 -j DNAT --to-destination 10.0.0.2:995 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p udp -m udp --dport 995 -j DNAT --to-destination 10.0.0.2:995 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.2:80 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p udp -m udp --dport 80 -j DNAT --to-destination 10.0.0.2:80 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p tcp -m tcp --dport 53 -j DNAT --to-destination 10.0.0.2:53 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p udp -m udp --dport 53 -j DNAT --to-destination 10.0.0.2:53 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p tcp -m tcp --dport 25 -j DNAT --to-destination 10.0.0.2:25 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p udp -m udp --dport 25 -j DNAT --to-destination 10.0.0.2:25 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p tcp -m tcp --dport 110 -j DNAT --to-destination 10.0.0.2:110 iptables -t nat -A PREROUTING -d 202.63.167.192 -i eth0 -p udp -m udp --dport 110 -j DNAT --to-destination 10.0.0.2:110 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.2:80 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p udp -m udp --dport 80 -j DNAT --to-destination 10.0.0.2:80 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p tcp -m tcp --dport 53 -j DNAT --to-destination 10.0.0.2:53 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p udp -m udp --dport 53 -j DNAT --to-destination 10.0.0.2:53 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p tcp -m tcp --dport 110 -j DNAT --to-destination 10.0.0.2:110 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p udp -m udp --dport 110 -j DNAT --to-destination 10.0.0.2:110 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p tcp -m tcp --dport 995 -j DNAT --to-destination 10.0.0.2:995 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p udp -m udp --dport 995 -j DNAT --to-destination 10.0.0.2:995 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p tcp -m tcp --dport 25 -j DNAT --to-destination 10.0.0.2:25 iptables -t nat -A PREROUTING -s 192.168.0.0/255.255.255.0 -d 202.63.167.192 -i eth2 -p udp -m udp --dport 25 -j DNAT --to-destination 10.0.0.2:25 ################### default policy of INPUT, OUTPUT and FORWARD is drop. I want to protect LAN hence routing web and mail request to eth1(10.0.0.2). Web server is serving properly for LAN as well as Outside(Internet) users. For mail server access from LAN, I am using Outlook Express from client machine. setting of senamil and outlook are O.K. since I am using same settings on my othet DMZ firewall network where it works perfectly allright. PROBLEM : When I try to connect from client outlook. I get follwoing message while receiving and sending mails at outlook express error box. ############ The connection to the server has failed. Account: 'A.D.Shintre', Server: 'mail.networkshastrihall.com', Protocol: SMTP, Port: 25, Secure(SSL): Yes, Socket Error: 10061, Error Number: 0x800CCC0E The connection to the server has failed. Account: 'A.D.Shintre', Server: 'mail.networkshastrihall.com', Protocol: POP3, Port: 995, Secure(SSL): Yes, Socket Error: 10061, Error Number: 0x800CCC0E ################### Is it iptables problem? should not be since no drop policy is adopted. What is this error "Socket Error:" any idea? Help appreciated. __________________________________ Do you Yahoo!? Vote for the stars of Yahoo!'s next ad campaign! http://advision.webevents.yahoo.com/yahoo/votelifeengine/